Citations

... move significant distances during packet transit times. Thus, for capacity analysis, we can view mobile networks as effectively static. The following simplification of an analysis by Gupta and Kumar =-=[8]-=- estimates the per node capacity to be expected in an ad hoc network. Radios that are sufficiently distant can transmit concurrently; the total amount of data that can be simultaneously transmitted fo...

...e per node throughput actually available was about 50 times smaller than the apparent capacity. The loads used in other ad hoc routing studies are consonant with this; for example, both Karp and Kung =-=[9]-=- and Broch et al. [2] limit the total offered load to about 60 Kbps despite using 2 Mbps radios. The interaction of ad hoc routing and capacity suggests that any evaluation of an ad hoc network requir...

...e, this simple analysis omits the constant factors which determine whether any particular networks will have a useful per node throughput. A common observation in analyses of ad hoc routing protocols =-=[2, 10, 4]-=- is that capacity is the limiting factor; that is, the symptom of failure under stress is congestion losses. A high volume of routing queries or updates, caused by mobility or a large number of nodes,...

...y support minimumenergy routing. We also focus on capacity limits imposed by multihop traffic patterns rather than by aggregate interference. We assume that nodes are stationary. Grossglauser and Tse =-=[6]-=- consider ad hoc networks of mobile nodes, showing that long term per node throughput can stay constant in a network where node movement process is ergodic with a stationary distribution uniform over ...

... networks. 2. 802.11 Background This paper assumes use of the IEEE 802.11 [3] Distributed CoordinationsFunction, the access method used in ad hoc mode. To reduce collisions caused by hidden terminals =-=[1]-=- in the network, 802.11 uses a four-way RTS/CTS/Data/Ack exchange. In brief, a node that wishes to send a data packet first sends an RTS (request to send) packet to the destination. If the destination...

...e, this simple analysis omits the constant factors which determine whether any particular networks will have a useful per node throughput. A common observation in analyses of ad hoc routing protocols =-=[2, 10, 4]-=- is that capacity is the limiting factor; that is, the symptom of failure under stress is congestion losses. A high volume of routing queries or updates, caused by mobility or a large number of nodes,...

...e, this simple analysis omits the constant factors which determine whether any particular networks will have a useful per node throughput. A common observation in analyses of ad hoc routing protocols =-=[2, 10, 4]-=- is that capacity is the limiting factor; that is, the symptom of failure under stress is congestion losses. A high volume of routing queries or updates, caused by mobility or a large number of nodes,...

...d interaction between ad hoc forwarding and the 802.11 MAC. The section starts with simple scenarios and works towards complex situations that are more likely to be seen. The simulator used is the ns =-=[5]-=- simulator with the CMU wireless extensions [7] whose parameters are tuned to model the Lucent Wavelan card at a 2 Mbps data rate. Note that one node can interfere with packet reception at another nod...

...ne how ad hoc forwarding interacts with the 802.11 MAC and show that the use of 802.11 instead of a global scheduling scheme does not seem to affect the asymptotic bound on per node capacity. Shepard =-=[13]-=- considers limits on capacity imposed by aggregate interference from many senders spread over a large area, concluding that such networks are scalable. He points out that capacity can be increased wit...

... Nandagopal et al. [12] propose an algorithm that gives each flow in the network a fair allocation of capacity no matter how much more contention it perceives in comparison to other flows. Luo et al. =-=[11]-=- propose an algorithm that, in addition to giving each flow its fair share, maximizes the total network capacity by giving more chances to flows whose transmissions cause less interference. The propos...

... 802.11 MAC. The section starts with simple scenarios and works towards complex situations that are more likely to be seen. The simulator used is the ns [5] simulator with the CMU wireless extensions =-=[7]-=- whose parameters are tuned to model the Lucent Wavelan card at a 2 Mbps data rate. Note that one node can interfere with packet reception at another node even when they are too far apart for successf...